Platforms like Apple TV or Google Play Movies allow you to purchase individual seasons in high quality (VF or VOSTFR) legally.
Sites like Cpasbien are often mirrored or faked, leading users to download malware or "adware" instead of the show.
Downloading copyrighted content via P2P (peer-to-peer) networks can lead to notices from authorities (like Arcom in France).
While it might seem like the easiest way to catch up on Season 4, using torrent sites often comes with downsides:
Here is a blog post structure designed for a TV fan site that addresses this topic while keeping things safe and legal. Finding "Legacies" in French: Your Ultimate Viewing Guide
While searching for "Legacies saison French HDTV cpasbien" might lead you to what you want, the safest and highest-quality experience always comes from official sources. Not only do you get better video quality, but you also support the creators so we can get more stories from the supernatural world!